Thailand Tilts Away From the U.S.

The military snubs its longtime ally to buy Chinese subs.

June 30, 2015 7:33 pm ET

Thailand’s navy has long pushed to buy conventional submarines, with U.S. allies Germany or South Korea the expected suppliers. So the decision to buy Chinese boats, reported Friday by the Bangkok Post, suggests America’s oldest ally in Asia is edging toward Beijing.

This development is particularly concerning because the two countries’ militaries have a deep and abiding relationship. The U.S. helped Bangkok fight a communist insurgency and flew bombing missions from Thai air bases during the Vietnam War. Started more than...